The present invention relates to end-to-end abutting connection of fluid handling pipes. More particularly, the invention relates to a pipe connection adapted for end-to-end connection of pipes having dissimilar ferrules welded to the ends thereof.
Heretofore, pipes, for example, those used for conveying liquids or flowable food products have often been connected together by attaching abutting flanges to the ends of the pipes. In order to attach such flanges it has been common to manufacture a ferrule having a flange, which ferrule has, at its opposite end, a section having a diameter equal to that of the pipe and is thus adapted to be welded to an end of the pipe. Often it is desired to form and end-to-end connection between pipes having dissimilar end fittings
For example, flanges are often provided with grooves in the abutting face surfaces for retention therein of a gasket, in order to ensure a leakproof connection of the two abutting pipe sections. However, to avoid compression and extrusion inwardly into the pipe of the gasket material, thus to avoid partial obstruction of fluid flow in the pipe, ferrules are sometimes provided which use metal-to-metal abutment. It is difficult, however, to effectively connect ferrules adapted for such metal-to-metal abutment with ferrules that are not.
Additionally, a further problem occurs in that when a ferrule is welded to the pipe, there is a tendency for the pipe to shrink slightly in the vicinity of the weld. This causes a small amount of tilting of the faces of the flange away from the central axis so that they will not be able to come into flush abutment with each other.
In view of the foregoing difficulties, a need has existed for an improved flange configuration. A need has also existed for an improved method of forming such flanges on the ends of pipes to ensure a flush face to face contact of the flange ends and leakproof abutment thereof.